cmake/target.cmake defines macros for the supported platforms, this
commit changes predefined system macros to our own macros.
__linux__ --> OS_LINUX
__APPLE__ --> OS_DARWIN
__FreeBSD__ --> OS_FREEBSD
Official docs:
Some headers from C library were deprecated in C++ and are no longer
welcome in C++ codebases. Some have no effect in C++. For more details
refer to the C++ 14 Standard [depr.c.headers] section. This check
replaces C standard library headers with their C++ alternatives and
removes redundant ones.
Before it was silently try-catched for messages with additional {}, and
it is very easy to trigger, i.e.:
SELECT toDateTime(format('{}-{}-01 00:00:00', '2021', '1'))
Will print:
Code: 41. DB::Exception: Received from localhost:9000. DB::Exception: Cannot parse datetime 2021-1-01 00:00:00{}: Cannot parse DateTime from String: while executing 'FUNCTION toDateTime(format('{}-{}-01 00:00:00', '2021', '1') :: 3) -> toDateTime(format('{}-{}-01 00:00:00', '2021', '1')) DateTime : 2'.
This will avoid hiding some exceptions in logs, when the server is under
high memory pressure (i.e. when any new allocation will lead to
MEMORY_LIMIT_EXCEEDED error).
This became more relevent after all memory allocations was tracked with
MemoryTracker, by falling back to total_memory_tracking, in #16121
Contains error codes with number of times they have been triggered.
Columns:
- `name` ([String](../../sql-reference/data-types/string.md)) — name of the error (`errorCodeToName`).
- `code` ([Int32](../../sql-reference/data-types/int-uint.md)) — code number of the error.
- `value` ([UInt64](../../sql-reference/data-types/int-uint.md)) - number of times this error has been happened.
**Example**
``` sql
SELECT *
FROM system.errors
WHERE value > 0
ORDER BY code ASC
LIMIT 1
┌─name─────────────┬─code─┬─value─┐
│ CANNOT_OPEN_FILE │ 76 │ 1 │
└──────────────────┴──────┴───────┘
